The V3 API in OpenStack Identity (Keystone) 2013.1 before 2013.2.4 and icehouse before icehouse-rc2 allows remote attackers to cause a denial of service (CPU consumption) via a large number of the same authentication method in a request, aka "authentication chaining."

The ec2tokens API in OpenStack Identity (Keystone) before Havana 2013.2.1 and Icehouse before icehouse-2 does not return a trust-scoped token when one is received, which allows remote trust users to gain privileges by generating EC2 credentials from a trust-scoped token and using them in an ec2tokens API request.

OpenStack Identity (Keystone) before 2013.2.4, 2014.1 before 2014.1.2, and Juno before Juno-2 does not properly handle chained delegation, which allows remote authenticated users to gain privileges by leveraging a (1) trust or (2) OAuth token with impersonation enabled to create a new token with additional roles.